Conduit bender



Jan. 9, 1951 smu 2,537,254

I 35 1' 421.," i I 37--- n I) I I 1 iii INVENTOR.

1 I Z HAP/9V 50 77/15 Ii 32 2 2 fi/ T 1Qfiz- I w ATTORNEY Jan. 9, 1951H. BLYTHE 2,537,254

CONDUIT BENDER 2 Sheets-Sheet 2 Filed June 30, 1949 INVENTOR. HARE) 5LYTHE Patented Jan. 9, 1951 UNITED- STATES PATENT OFFICE 4 Claims.

This invention relates to a conduit bender, and has for its principalobject the provision of a simple and highly efiicient device which canbe preset for producing bends of any desired degree in both pipe andthin-walled conduit or tubing of various diameters.

Other objects and advantages reside in the detail construction of theinvention, which is designed for simplicity, economy, and efiiciency.These will become more apparent from the following description.

In the following detailed description of the invention, reference is hadto the accompanying drawing which forms a part hereof. Like numeralsrefer to like parts in all views of the drawing and throughout thedescription.

In the drawing:

Fig. 1 is a plan view of the improved bender;

Fig. 2 is a side view thereof;

Fig. 3 is an enlarged end view of the bending portion of the bender;

Fig. 4 is a detail, perspective view of a pipe clamp employed in theimproved bender;

Fig. 5 is a fragmentary detail section, taken a the line Fig. 11 is asimilar section, illustrating the bending sector in the expanded pipe orconduit bending position.

The improved bender is mounted on a supporting frame consisting of twoinverted, U- shaped side leg members l3 preferably formed from metalpipe "and joined by means of cross frame members l4 welded or otherwisesecured therebetween. The cross members l4 support two longitudinallyextending, parallel roller guides l5 between which a pair of flatrollers l6 and a double groove roller l'l extend, for receiving the pipeor tubing to be bent.

A vertical side plate I8 is welded to one of the leg supports l3 andextends upwardly. therefrom.

A channel guide track I9 is secured to each ver-' tical edge of theplate l8 and acts to hold a slide plate 20 in place thereon. The slideplate. is vertically movable and may be adjusted in any desired verticalposition by means of a jack screw 2|. The screw 2| is threaded through afoot member 22 mounted on a leg 23 extending downwardly from the sideplate 20 and is supported and rotatably mounted in a foot flange formedon the side plate l8 and in one of the cross members l4.

A tubular spindle 24 is fixedly mounted in. the slide plate 20 andextends horizontally outward therefrom to support a bearing collar 25formed on a bending sector member 26. The vertical position of the slideplate 20 can be determined from an index pointer 21 which indicatespositions on a scale 28 on one of the track channels l9.

The bending sector sleeve 25 is provided with a handle socket 29 forreceiving a suitable. lever handle 30 which is locked in place in, thesocket 29 by means of a set screw 3|. The bending sector is providedwith a clamp-supporting arm 32 extending radially downward and sidewardfrom the sector 26. l

A swinging pipe-clamping member 33 is mounted on a hinge pin 34 at thebottom of the arm 32 and is provided at its top with a hook35 which canbe hooked over a projecting lug on the upper portion of the arm 32. Theclamp 33 is provided with two pipe-engaging notches, a large diameternotch 36 and a small diameter notch 31.

The sector member 26 terminates at its peripheral edge in a groove whichforms one-half of a large diameter pipe-receiving groove 38. The otherhalf of the groove 38 is formed by means of a side arc member 39 whichis attached to the sector member 26 by means of suitable attachmentscrews 40 which extend through the sector member 26 and are threadedinto the side are member 39. The outer face of the sector 26 is formedwith an arcuate curved shoulder 6| which forms one-half of a smalldiameter pipereceiving groove 4|. The other half of the groove 4| isformed by means of an arcuate side plate 42 which is attached to thesector member 26 by means of suitable attachment screws 43 which extendthrough the side plate 42 and are threaded into the sector member 26.The tangential axes of the grooves 38 and 4| align with the axes of thenotches 36 and 31 in th clamp 32 and with the grooves in the groovedroller ll.

The screws 40 extend through slotted. screw holes 44 in the sectormember 26, and the screws 43 extend through similarly slotted screwholes. 45 in the side plate 42. This allows the side arcl member 39 andthe arcuate side plate 42 to be shifted circumferentially. The purposeof this circumferential shift is to vary the width of the grooves 38 and4|. This is accomplished by forming raised lugs 46 on the sector member26 which fit into receiving notches 41 on the side are member 39 and theside plate 42. When the lugs 46 are in the notches 4'! the grooves 38and M are of minimum width. This width can be increased a predeterminedamount by loosening the screws 49 and 43 and slipping the arc member 39and the side plat 42 circumferentially so that the lugs 46 will rest onth surface of the sector member 26 and not in the notches 41, as shownin Fig. 11.

The sector sleeve 25 is held in place on the spindle 24 by means of alatch pin 43 which is projected outwardly from the spindle by means" ofa latch spring 49, and which can be pressed inwardly to remove thesleeve 25 by means of a' its four positions by means of a latch spring55' which selectively engages any one of four receiving notches 56 inthe back of the turret block 53, as shown in Fig. 8. The head of theuppermost stop screw 52 is in the path of, and is contacted by, a lug5'! formed on and projecting from the handle socket 29. I

The bender can, of course, be designed to handle two difiering sizes ofpipe or conduit of any desired diameter. The usual bender is designed.to handle inch and V inch pipe or tubing. A different sector member canbe slipped in place on the spindle, however, for handling other sizes.

Operation Let us assume that the inch and inch sec tor is in place andthat it is desired to bend inch tubing to a 90 arc. The crank 58 isrotated to position the pointer 23 opposite the 90 bend mark on theindex 28. The tubing is inserted over the rollers l6 and Ill to bringthe start of the bend below the axis of the sprindle 24. The turretblock 53 is rotated to position the proper screw 52 upwardly for a inchtubing bend. The clamp 33 is swung into place beneath the tubing and thehandle 30 is pulled rearwardly as far as possible. This brings the lug51 against the uppermost stop screw 52, producing a perfect 90 bend inthe tubing.

Should a 90 bend be desired in inch tubing,

it is placed in the groove of the roller i1 below the small groove 4!and the settings are made at the pointer 2'1 and at the rotating turrethead 53 to suit A; inch tubing. The handle 39 is then rotated rearwardlyas far as possible. 7, v

For bending pipe it is necessary that the grooves38 and ll be widened,since the outside diameter of pipe exceeds the Outside diameter oftubing. This is done as before described by loos-f ening the screws 40and 43 and slipping the arc member 39 and the side plate 42circumferentially so that they will rest on their lugs 46 to produce awidened groove, as shown at the groove ii in Fig. 9. ,Thesettings at 2'!and 53 are then properly made to accommodate pipe bends.

A scale is furnished with each machine, telling 4 the operator theproper settings of the turret head 53 and the pointer 21 for any desiredpipe or tubing. A second pointer 59 is mounted over an index 60 on thesleeve 25 to give the desired degrees for bends less than While aspecific form of the improvement has been described and illustratedherein, it is to be understood that the same may be varied, within thescope of the appended claims, without departing from the spirit of theinvention.

Having thus described the invention, what is claimed and desired securedby Letters Patent is:

1. In a pipe bender having a rotary sector member provided with anarcuate pipe-receiving groove for forming a bend in a pipe, means forvarying the width of the groove in said sector member to adapt saidgroove to either pipe or tubing, comprising: a half groove formed insaid sector member; an arcuate side plate, the other half groove beingformed in said side plate;

screws attaching said side plate to said sector member; projections onsaid sector member; and complementary receiving depressions in said sideplate fOr receiving said projections, said screws being positioned inslotted screw holes so that said side plate ma be shiftedcircumferentially to place said projections either in or out of saiddepressions.

2. A pipe bending sector for pipe bending devices comprising: bendingsector having an arcuate edge; a transversally curvated groove in saidedge forming one-half of a, groove; a side are member corresponding inradius to said sector and having similarly curvated arcuate edge formingthe other half of a 180 groove, said side arc member beingcircumferentially shiftable relative to said sector; and means acting toseparate said arc member from said sector in consequence of the relativecircumferential movement th'ereb'etween.

3. A pipe bending sector for pipe bending devices comprising: a bendingsector having an arcuate edge; a transversally curvated groove in saidedge forming one-half of a 180 groove; a

' side arc member corresponding in radius to said sector' and havinga'similarly curvated arcuate tacting surfaces between said arc memberand said'sector being such that the two will be spaced further apart atone circumferential position than another.

'4. A pipe bending sector for pipe bending devices comprising: a bendingsector having an arcuate edge; a 'transversally curvated groove in saidedge forming one-half of a 180 groove; a'

side are member corresponding in radius to said sector and having asimilarly curvated arcuate edge forming the other half of a 180 groove,said side arc member being circumferentially shiftable relative to's aidsector; means acting to separate said am member from said sector inconsequence of the relative circumferential move.

ment therebetween; an arcuate shoulder of less radius than said sectorprojecting concentrically from one face thereof, a transversally arcuategroove insaid shoulder formingone-half of a second 180? grooveyanarcuate side plate having; the ,remainder of' said latter. groovesecured against said sector below said shoulder; and

means for varying the spacing between said sector and said arcuate sideplate.

HARRY BLYTHE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Number Number 10 Name Date Schalk Feb. 9,1932 Redmer Jan. 21, 1941 Shaw Dec. 23, 1941 St. Clair May 23, 1944 DuerSept. 12, 1944 Jimerson June 28, 1949 FOREIGN PATENTS Country Date GreatBritain Apr. 13, 1908 OTHER REFERENCES P. 121, American Machinist, Mar.29, 1945.

